A review of thermal and hygrothermal requirements in historic churches

Upgrading the building fabric of historic churches is challenging due, in part, to decorative finishes, important religious artefacts and the desire to preserve cultural heritage. This paper reviews current literature, aiming to establish the thermal and hygrothermal requirements of historic churches. Main observations from the literature are that many limits exist when trying to improve the energy performance of historic building fabric. Natural control of external temperature and humidity cycles is exhibited by the building fabric, resulting in some retrofit technologies causing an increase in moisture accumulation. However, some novel technologies may help to improve fabric performance without the loss of historic value. Historic fabric energy performance may be better than expected due to lack of knowledge of historic materials. Artefacts contained within the building often dictate the range of acceptable temperature and relative humidity fluctuations. Ventilation and installed heating systems can assist in maintaining the correct internal environment.